Endocrinology Flashcards
What concurrent medication can reduce the uptake of levothyroxine?
Iron, calcium carbonate, give at least 4 hours apart
What can cause lower than expected levels of HbA1C?
Sickle-cell anaemia
GP6D deficiency
Hereditary spherocytosis
What can cause higher than expected levels of HbA1c?
Vitamin B12/folic acid deficiency
Iron-deficiency anaemia
Splenectomy
What dose of atorvastatin is recommended for secondary prevention?
80mg
Describe MEN type 1
Parathyroid (95%): hyperparathyroidism due to parathyroid hyperplasia
Pituitary (70%)
Pancreas (50%): e.g. insulinoma, gastrinoma (leading to recurrent peptic ulceration)
Also: adrenal and thyroid
Describe MEN type 2a
Medullary thyroid cancer (70%)
2 P’s
Parathyroid (60%)
Phaeochromocytoma
Describe MEN type 2b
Medullary thyroid cancer
Phaeochromocytoma
Marfanoid body habitus
Neuromas
What is the treatment for toxic multinodular goitre?
Radioiodine therapy
Name some glucocorticoid side effects
Endocrine: impaired glucose regulation, increased appetite/weight gain, hirsutism, hyperlipidaemia
Cushing’s syndrome: moon face, buffalo hump, striae
musculoskeletal: osteoporosis, proximal myopathy, Avascular necrosis of the femoral head
Immunosuppression: increased susceptibility to severe infection, reactivation of tuberculosis
Psychiatric: insomnia, mania, depression, psychosis
Gastrointestinal: peptic ulceration, acute pancreatitis
Ophthalmic: glaucoma, cataracts
Dermatological: acne
Suppression of growth in children
Intracranial hypertension
Neutrophilia
How do sulphonylureas work?
Sulfonylureas are oral hypoglycaemic drugs used in the management of type 2 diabetes mellitus. They work by increasing pancreatic insulin secretion and hence are only effective if functional B-cells are present. On a molecular level they bind to an ATP-dependent K+(KATP) channel on the cell membrane of pancreatic beta cells.
Name some side effects of sulphonylureas
Common adverse effects:
Hypoglycaemic episodes (more common with long-acting preparations such as chlorpropamide)
Weight gain
Rarer: Hyponatraemia secondary to syndrome of inappropriate ADH secretion Bone marrow suppression Hepatotoxicity (typically cholestatic) Peripheral neuropathy
Name some causes of a normal anion gap metabolic acidosis
Addison’s
Bicarbonate loss: GI (e.g. diarrhoea) or renal (e.g. renal tubular acidosis)
Chloride excess
Diuretics (e.g. acetazolamide)
Name some causes of a high anion gap metabolic acidosis
Lactate
Toxins (e.g. methanol, paracetamol, propylene glycol)
Ketones
Renal failure
Describe some features of type 1 RTA
Type 1 RTA (distal)
inability to generate acid urine (secrete H+) in distal tubule
causes hypokalaemia
complications include nephrocalcinosis and renal stones
causes include idiopathic, rheumatoid arthritis, SLE, Sjogren’s, amphotericin B toxicity, analgesic nephropathy
What is Bartter’s syndrome?
Bartter’s syndrome is an inherited cause (usually autosomal recessive) of severe hypokalaemia due to defective chloride absorption at the Na+ K+ 2Cl- cotransporter (NKCC2) in the ascending loop of Henle. It should be noted that it is associated with normotension (unlike other endocrine causes of hypokalaemia such as Conn’s, Cushing’s and Liddle’s syndrome which are associated with hypertension).
